Electro-magnetic plunger pump



May 6, 1 58 J. w. DICKEY 2,833,221

ELECTRO-MAGNETIC PLUNGER PUMP Filed Oct. 27 1954 2 Sheets-Sheet l llllINV ENTOR. 70f: Walla/c7 WITNESS NE Y May 6, 1958 J. w. DICKEYELECTRO-MAGNETIC PLUNGER PUMP 2 Sheets-Sheet 2 Filed Oct. 27, 1954yak/v70.

WITNESS:

United States Patent John W. Dickey, Newfield, N. Y., assignor to BendixAviation Corporation, a corporation of Delaware Application October 27,1954, Serial No. 464,940

Claims. Cl. 103-53 The present invention relates to an electromagneticplunger pump and more particularly to a reciprocating spring-actuatedpiston pump for transferring liquids.

This invention is an improvement on the 'pump disclosed in the patent toDickey et a1. 2,472,067 by incorporation therein of a number of novelfeatures which cooperate to secure the objective of a pump which is ofsimple and economical design, and is readily assembled by methods whichinsure permanently tight joints free from leakage or contamination.

It is another object to provide such a device which is adapted for easyinstallation in various positions and attitudes.

It is another object to provide such a device incorporating convenientmeans for adjusting the output pressure of the pump.

It is another object to provide such a device which is hermetricallysealed by a soldering operation in which there is no possibility ofsolder or flux gaining access to the interior of the pump.

It is another object to provide such a device including an air domechamber which may be sealed and tested prior to assembly on the pump.

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawing in which:

Fig. l is a vertical substantially mid-sectionalview of a preferredembodiment of the invention, parts of the electrical circuit being showndiagrammatically;

Fig. 2 is a detail in elevation of the shunt resistor ele ment;

Fig. 2(a) is an end view of the core for the same;

Fig. 3 is a side elevation of the spool for holding the solenoid coil;

Fig. 4 is a top view of the same;

Fig. 5 is a detail in perspective of the mounting clamp for the pump;and

Fig. 6 is a perspective detail of the elastically deformable sleeveembracing the pump within the mounting bracket.

In Fig. 1 of the drawing there is illustrated a hollow cylinder 1 ofsuitable non-magnetic material within which a hollow magnetic piston 2is slidably mounted. An electro-magnet 3 surrounds the cylinder andpiston and is mounted coaxially within a cylindrical casing 4 ofmagnetic material by means of annular pole pieces 5 and 6 at the endsthereof. The casing 4 extends beyond the pole pieces 5 and 6 to providean inlet chamber 7 and an interrupter chamber 8, and the non-magneticcylinder 1 extends at its ends beyond the pole pieces 5 and '6 into theinlet and interrupter chambers respectively.

The inlet chamber 7 is provided with an inlet nipple fitting 9 forattachment of ,hose 11, and is closed by a detachable cap 12 whichcarries a mounting cup member 13 on which a permanent magnetic collectorelement 14 is suitably fixed as indicated at 15. The pole piece 5 isformed with a shoulder 16 having the same diameter as the mounting cup13, and a cylindrical filter ber and shoulder to thereby filter theincoming liquid.

prior to its entry into the pump cylinder 1.

The input end of the cylinder 1 is internally threaded as shown at 18,and a valve nipple 19 is threaded into the cylinder for longitudinaladjustment therein, which may be facilitated by the provision of spannersockets 21 in its lower end. Nipple 19 is formed with a tapered valveseat 22 against which a check valve plunger 23 is pressed by a valvespring 24 which is maintained under slight compression by a cup-shapedspider member 25 forming a guide for the .valve stem 26 and having aflange 27 seated in a counter-bore in the nipple 19.

A compression spring 28 is located within the lower end of the pumpcylinder 1, resting on the flange 27 of spider 25 and hearing at itsupper end on the lower end of the piston 2 whereby said spring biasesthe piston toward the discharge end of the cylinder as illustrated. Asecond check valve 29 is retained on the lower end of the piston 2 bymeans of a seat member 31 having a skirt 32 which is expanded into anundercut counterbore in the end of said piston. This is convenientlyaccomplished by introducing a spider guide member 33 which is originallyof dished formation, and flattening it out in order to expand said skirtat circumferentially spaced points as illustrated at 34.

A cup-shaped partition member 35 is provided with a centrally locatedcylindrical shoulder 36 which is forced into the upper end of thecylinder 1 and preferably soldered or brazed thereon in order to formv atight seal.

The rim 37 of the partition member 35 is spun over a lip 38 on the upperend of the casing member 4 and is soldered thereto as indicated at 39 toform a closure for the interrupter chamber 8. A buffer spring 41 ispreferably located in a counter-bore 42 in the upper end of piston 2 andbears against the partition member 35 adjacent a central opening 43therein, to cushion the reciprocation of the piston at times when it maybe operated while the pump is empty.

A domed cap member 44 provided with an outlet nipple fitting 45 ismounted on the outlet end of the casing 4 by bending its rim 46 over thelip 38 of the casing and soldering the joint as shown :at 39simultaneously with the attachment of the partition member 35. The cap44 is formed with an annular shoulder 47, and an impervious circularflexible diaphragm 48 is seated on said shoulder and maintained insealed connection therewith by means of a sealing ring 49'having a pressfit against said shoulder, thereby forming an output chamber 50 in saidcap between the partition 35 and diaphragm 48.

In the manufacture of the pump, the diaphragm 48 is mounted and sealedin the cap member 44 prior to assembly of the cap, so that the tightnessof the seal may conveniently betested While disassembled. Assembly isthen accomplished by seating the partition member 35 and cap 44 innested relation on the lip 38 of casing 4, and crimping the edgesthereof around said lip as shown. This operation makes a tight jointeven without the solder seal, whereby any possibility of solder or fluxentering the pump during the soldering operation is prevented.

Means for energizing the solenoid 3 intermittently to causereciprocation of the plunger 2 is provided comprising a battery 51 whichis grounded at 52 and connected through a switch 53 and cable 54 to oneterminal lead 55 of the solenoid. The other terminal lead 56 isconnected to a fixed contact 57 which cooperates with a movable groundedcontact 58 mounted on a cradle 59 carrying a permanent magnet whichcauses the cradle to tilt and closes said contacts when the piston 2approaches the upper end of its stroke. interrupter mechanism is thePatented May 6, 1958 3 same in structure and operation as that shown anddescribed in Patent 2,472,067 above referred to, so that furtherdescriptionthereof is deemed unnecessary. 1

The terminal wires 55 and 56 of solenoid 3 are shunted by a resistor 61which is preferably constructed as best shown in Fig. 2. The solenoid 3is mounted on a spool 62 ('Figs. 3 and 4) of suitable insulatingmaterial having terminal flanges 63, 64 provided with dove-tail notches65 receiving the complementarily formed ends 66 and 67 of a strip ofinsulating material 68 forming the core on which the resistor 61 iscoiled. The upper end of the mount 68 is preferably provided withslotted recesses 69 forming convenient anchorages for the terminal wires55 and 56 of the solenoid, as well as for the ends 71 and 72 of theresistor which are wound around said terminal wires and solderedthereto. e v

In order to form a hermetically sealed connection to the battery cable54 a metallic tube 73 is sealed within a nipple 74 suitably mounted in afluid tight manner in an opening 75 in the side of the casing 4. Thissealing connection is preferably formed by means of a fused vitreousmaterial as indicated at 76 forming a permanent rigid and leak-proofjoint which also insulates the tube 73 from the casin g. The end of thecable 54, and the terminal wire 55 with the end 71 of the resistor woundaround it are passed through the tube 73 in overlapping relation, andare rigidly sealed together by a single soldering operation as shown at77. The junction of the battery cable to the pump leads is preferablycovered by a weather-proof enclosure 70 in the form of a metallic sleevewith acore. of

rubber or the like formed around the junction. The opposite terminalwire 56 of the solenoid with the end 72. of the resistor wire woundabout it is led through a nipple 80 formed on one end flange 63 of thespool 62, traversing the pole piece 6 and attached by a single solderingoperation to the fixed contact 57.

Means are provided for mounting the pump conveniently in the mostadvantageous relation to the inlet and outlet conduits of any particularinstallation. For this purpose a clamping bracket 78 (Fig. is formed asa band for surrounding the body of the pump having a plurality ofopenings 79 for alternatively receiving the nipple 74 to thereby permitthree optional orientations of the pump. The bracket 78 is formed withlaterally extending feet 81, 82 for attachment to a fixed support in anysuitable manner, and is clamped to the pump 'by a bolt 83 or the like.

In order to insure quietness of operation a flanged split bushing 84 ofelastically deformable material is preferably interposed between thebracket 78 and the body of the pump. 7

In installing' the device, the bracket 78 is applied to the pump withthe cushioning sleeve 84 contained therein, in such position as toorient the pump most conveniently to the input and output conduits, thusreducing the necessity for angular pipe fittings. It will be undersoodthat the bracket is sufiiciently elastic to be expanded as necessary forthe insertion of the nipple 74 in the selected opening 79. The sleeve 84may be sufl'iciently elastic to be applied by stretching but if desiredmay be slit as indicated at 85 to permit its application to the pump.

After the pump has been mounted and the tubular and electricalconnections completed, closure of switch 53 causes cnergization ofelectro-magnet 3 which accordingly draws the plunger 2 downwardlycompressing the spring 28 until the contact 58 is permitted to move awayfrom the fixed contact 57. The spring 28 then actuates. the piston onits discharge stroke, at the endof which contacts 57, 58 are againclosed. The fluctuations of pressure in the output chamber 50 arecushioned by the air dome provided by the diaphragm 48.

Adjustment of the output pressure is readily effected by removing thecover 12 and rotating the nipple 19 by means of an appropriate spanner.By this means, the pressure of the spring 28 is adjusted to provide thedesired output pressure of the pump.

Although but one embodiment of the invention has been shown anddescribed in detail it will be understood that changes may be made inthe design and arrangement of the parts without departing from thespirit of the invention.

I claim:

7 i. In an electromagnetic pump a cylinder of non-magnetic material, ahollow magnetic piston slidably mounted therein, an electromagnetsurrounding the cylinder and piston, a cylindrical casing of magneticmaterial, annular pole pieces at the ends of the electromagnetsupporting the magnet and cylinder assembly coaxially in the casing,said casing extending beyond both said pole pieces to provide an inletchamber at one end and an interrupter chamber at the other end formedwith a terminal radial lip, said cylinder extending into both saidchambers; a cup-shaped partition member formed with a centrally locatedcylindrical shoulder having a sealed connection to the outlet end of thepump cylinder, andhaving its rim tightly embracing said lip on the endof the casing, thereby forming a closure for the interrupter chamber, adomed cap member having a rim tightly embracing the rim of the partitionmember and the lip of the casing and externally sealed to the, casing,cooperating with said partition member to form an output chamber, meansfor yieldingly biasing the piston toward the output chamber, means forintermittently energizing the electromagnet to draw the piston towardthe input chambcr and valve means for transferring liquid from the inputchamber to the output chamber responsive to reciprocation of the piston;including further a flexible impervious diaphragm and means forhermetically sealing the rim of the diaphragm to the interior of the cupin,

ductor and wire traversing the nipple in opposite directions inoverlapping relation, and a fused metallic seal closing the nipple anduniting said conductor and wire.

3. An electromagnetic pump as set forth in claim'Z including further aresistor connected in parallel with the electromagnet, one terminal leadof the resistor also traversing said nipple and being united with theconductorfrom the power source and the terminal wire ofthe electromagnetby said fused metallic seal.

4. An electromagnetic pump as set forth in claim '1 in which the end ofthe cylinder which extends into the input chamber is internallythreaded, and the means for biasing the piston toward the output chambercomprises a compression spring hearing at one end on the piston, and anipple threaded in the input end of the cyiinclercarrying an input checkvalve and forming an adjustable abut- References Cited in the file ofthis patent UNITED STATES PATENTS 2,472,067 Dickey et al. June 7, 19492,669,186 Parker Feb. 16, 1954 2,673,522 Dickey ..Mar. 30, 1954

